The aim of the game is to take the enemy's standard (flag) from their castle and return it to the standard in your own castle, gaining 1 point each time. You must prevent the opposing team from taking your flag by blocking them from your castle (place barricades, lock doors or collapse tunn
els underground), or by killing them. Slain players will respawn in the Starting area within the game, so both sides are constantly fighting with a near (if not totally) equal numbered team. This is a safe game so if you die you will not lose items. Each game lasts for 20 minutes, and the team with the most points at the end of the game is the winner. You will gain two castle wars tickets if your team wins, and one ticket if both teams finish on the same amount of points. You will not gain more tickets if you kill another player or score a point. Castle Wars tickets are redeemable for a number of decorative armours and other rewards. For having more success in Castle Wars it is better to have a higher combat level, but lower level players can focus on the defensive measures mentioned below.

The only items allowed inside the Castle Wars area are potions, runes, and combat-related items such as armour - with the exception of helmets, hats, scarves and capes. Food cannot be brought in, but bandages can be obtained within the arena - which are used to heal players in the same way as food. Alchemy spells cannot be used during the game. Lunar spells such as Heal Other and Cure Me can not be used during the game. The dwarf multicannon cannot be brought into Castle Wars. Originally, players were allowed to bring their pet cats into the arena, but after many players complained, Jagex removed this ability.

Since this is a safe mini-game, players do not have to worry about dying because they will not lose their items. Unlike the Duel Arena, arrows will not be returned after each match. It is the player's responsibility to pick up any projectiles fired if they choose to do so. However, if an ava's device is used on Lathas before a player enters the game, he will collect ammunition for the player.

Also, if players are wearing armours or prayer symbols/books of the three gods (Saradomin, Guthix, Zamorak), they will have strange effects on the wearer if they enter the wrong portal. Saradomin will turn a player into a rabbit if they are wearing a Zamorak or Guthix symbol or armour when entering his portal; Guthix will turn them into a sheep if they are wearing a Saradomin or Zamorak symbol or armour upon entering its portal; and Zamorak will turn them into an imp if they are wearing a Saradomin or Guthix symbol or armour when entering his portal. Players transformed into a rabbit, sheep or imp cannot perform any tasks. They also cannot view menu screens other than private and public chat, music and settings. However, when the waiting period elapses and the game starts the player will be turned back to normal.

The large square formation covering most of the map is the actual arena. Inside the arena there are 2 smaller castles, one for each team. There are 4 levels to a castle. The ground floor has two outer walls facing into the arena, one with a large door that can be attacked and broken down (or barricaded by the defending team) and another with a smaller door that can be pick-locked (or locked by the defending team). The battlements on the ground floor are accessible via a staircase near the small door, and there is a catapu
lt on top of the outer wall. Within the walls there is a staircase leading to the battlements, a staircase leading to the second level, a ladder leading to the second level, and a ladder leading to the underground passages. There are tables where climbing ropes, rocks, barricades, pickaxes, toolboxes, and explosive potions are attainable. There is a tap, 2 bucket respawns, and a tinderbox respawn. When players die, they are returned to a respawn room in the appropriate castle.

The second floor contains a passage bent at a right angle, enveloping that team's spawn room, which is only accessible to the castle's team. There is a staircase leading to the next level. Inside the spawn room there is a bandage table, a tinderbox respawn, a ladder leading to the next level, and a portal to leave the current game. If any player does so, players on the same team in the waiting room will be asked if they wish to join the current game. The first to accept takes the previous player's space.

The third floor has a small inside wall enveloping a trapdoor that leads down to that castle's spawn room. The trapdoor is only usable by that castle's team. There is a one-square-wide passage around this wall. A staircase leading to the highest level is located against one of the walls.

The highest floor contains only a standard stand, which may or may not hold that castle's team's standard, depending on whether the enemy team has taken the standard or not.

The underground passage level can be accessed by two ladders in the middle of the arena or by a ladder from either team's castle. Either castle's ladder is located at opposite ends of the underground area, each with two passages towards the central cavern. At the mouth (facing the centre area) of each passage there is a deposit of rocks which may be removed or replaced with explosive potions or pickaxes. The central area is a small castle that has two ladders leading up to the centre of the arena's ground level. This area can be used for ranging and maging.

All players on the winning team receive three Castle Wars tickets. In the event of a 0-0 draw, all players receive two Castle Wars tickets. In the event of a draw at 1-1 or above, all players receive one Castle Wars ticket.

One catapult is located in each teams castle. Players may use the catapult if they have ammo, which they can obtain from tables on the first floor. After players have ammo, they can operate the catapult by clicking on it. A display will open up and players must then choose the X and Y coordinates of where they wish to fire, however often the shot will not go exactly where you aim. The highest X and Y coordinates are (30,30). All players near the area of impact, regardless of which team they are on, will take damage. Catapults can be destroyed by the enemy team using a tinderbox or an explosive potion. A toolkit can fix a broken catapult. A catapult that is on fire may be put out with a bucket of water. A good tactic with the catapult is to simply continue firing the catapult at coordinates (0,0). Be careful when using the catapult, because it is possible to harm and even kill your own team-mates with it.So be on the look out for renegade flying rocks!

These are located in the northeast and southwest points of the river. Players can jump from stepping stone to stepping stone to cross the river in the middle of the arena. The stepping stones have many uses, one main use is to escape the enemy team while capturing the flag. If the flag is dropped while standing on stepping stones it returns to the base. Players were once able to evade Ancient Magicks ice spells by crossing these stepping stones but this was recently changed so that bind spells now prevent you from crossing the stones.

The collapsible rocks are located in the caves below the arena. Using a pickaxe or an explosive potion, players may collapse the walls and fill the cave passageway with rocks, so that players may not pass. To get past the collapsed rocks, players must use either 2 explosive potions or a pickaxe or both. If rocks are collapsed on top of a player, he or she will die immediately. This is an excellent trick if you are running through the tunnels with the flag, as it gets rid of many chasers and blocks the rest, but they could also kill you. The best trick to use is when it's clear, put a barricade on one side of you and put one under you. Therefore, the player doesn't see it under you, and when they go to attack you they actually attack the barricade, then you can use an explosive potion on the wall, killing them.

Some useful tactics are:
A player bring a Dragon Spear, another player has an explosive potion. The player with a dragon spear uses its special to push someone into the rockslide area. Another player then collapses the area.
Placing a barricade beneath you negates any dragon spear effect on you from another player from the opposing team.
If there is a barricade beneath you, while a player tries to cross, he will be trapped in the rockslide area, which you can either immediately collapse or slowly mine.
In the caves, the most popular cave tunnel is the one on the right when coming down the ladder in a castle. The least popular is the one on the left.

The battle tactics in castle wars vary. Most of the time, each team will have at least one Ancient. The Ancient is often used to defend the castle from potential flag stealers by freezing them with ice spells. Once frozen this gives the melee people a chance to finish off the helpless thieves. Sometimes ancients will also have a dual ranging fight skill where they will freeze someone then range them. Ancients are also useful underground for stopping flag capturers as they try to infiltrate the castle from the underground passages. Most of the time however people choose to use melee because it is inexpensive rather than spending money on buying runes or arrows. This is typical because most Rangers or Ancients in the game waste runes very fast, this proves to be an issue because of how expensive most ancient or high level spells are. Mages and rangers tend to hang on the top of the castle near the catapult where they can see enemies storming the castle. They then strike down potential threats at the safety of the wall. This however may not last long if a powerful melee shows up on the wall. Then they will attack the mages and rangers taking them down quickly because of their low defense due to robes and dragon hide armour. This has however been compromised if there are enough mages or rangers to quickly take the melee player down. Lower level players tend to stay in the underground with a pick and collapse the tunnels with explosive potions and picks. Normally they will wait for the person to walk under the tunnel when trying to attack them, then collapse the tunnel instantly killing the other player. Other methods such as ranging them in order to lure them under the tunnel or using an ancient spell to trap them under the tunnel have been used, although not as often due to expenses. As for flag defending most people barracade the flag and the exit so that when a flag capturer comes they are trapped and quickly killed. Sometimes if players are quick enough in the beginning they may be able to capture the opposing teams flag room and defend it for the whole game taking the flag when it shows back up from a score. This may sometimes backfire if a low level player takes the flag. When this happens the other team will allow the player to leave the castle then take him down and take their flag and hold it. This may cause the defeat of the flag room raiding team.

To join a team, either enter the red portal (for Zamorak, God of Chaos) or the blue portal (for Saradomin, God of Wisdom). There is a possibility that the team you are trying to enter has too many people, so to keep the teams balanced you may not join it at that time. However, if you enter the green (for Guthix, God of Balance) portal, you are included in the team with the fewest number of people or is doing the worst in the game.

Once you join a team, you have to wait in an underground cavern until the next game starts. The Time remaining till the next game begins is displayed near the top of the screen in white print. The time to wait is always 5 minutes longer than the current game lasts, so if a game have 12 minutes left, the time to wait in the waiting area is 17 minutes. When a game has just finished, the next game will start in 5 minutes. If you need to leave, you can do so through the portal of the god's colour located inside the waiting area. Also, if you wear an item associated with a particular god in the opposite god's room you will be turned into either a sheep (if entering Guthix), rabbit (if entering Saradomin) or imp (if entering Zamorak) for the duration of your stay in the waiting room (you will be transformed back to your regular form for the game itself).

There are a number of special items that players can pick up while playing Castle Wars. These items are free and respawn immediately; however, they disappear once the game you are playing is over. (Also, if you choose to teleport back to the waiting area during a current game with these items in your inventory, you used to be able to keep them until you either entered the game and used them, or left the waiting room. However, Jagex recently changed this so the only item you keep when you exit the game is a tinderbox.)

Player setting up baricades to slow down enemies trying to reach the flag.

These can be picked up on one of the tables on the 1st floor of the castles. Barricades can be placed anywhere in the arena, and they are used to "block" the opposing team, hindering their ability to capture your flag. When somebody tries to walk around the barricade, the player must manually click to walk around it, otherwise he will be stuck.
If barricades are set up at the ends of the stairs, it will only allow one way direction transport only; for example if a player is going up a stairs and the other end is being block by barricades, the player can still go back up/down without leaving the stairs end or go through the barricade without destroying the barricade for the first time. However he/she cannot go back up/down to the stairs after leaving the stairs end, unless the barricades has been destroyed.
Barricades can be destroyed by setting them on fire, by manually attacking them, or by using an explosive potion. One of the downsides to setting up barricades is that a team can only set up 10 at a time and it also blocks the way of friendly forces.

Other tools which can be outside Castle Wars or can be obtained in Castle Wars are:

Bandages - Heal 10% of your total HP level (for example if your hitpoint level is 74, you get healed 7 points for every bandage), cure poison, and increase energy by 30%. Can be used on other players of the same team. Players may stock up on these greatly and become Medics for their team, breaking off and hiding near where they might be needed.

Climbing Ropes - Used to scale the battlements on the other team's castle. These ropes are one way (in other words you can't climb down them, only up.) and can not be cut off. Some people will sabotage the other team's wall by getting a full inventory of ropes and running to the other team's wall. They will try and set up as many ropes as they can on the wall before being attacked and killed. Some attack the catapult by setting up rope next to the enemy, climbing up and blowing the catapult up.

Pickaxes - For collapsing the underground cave walls to block the enemy. They are also used to clear the way through the collapsed walls. Players typically wait at the rocks and try to time their collapse perfectly as to hit a player trying to run through, although this is easier with explosive potions. Barricades may be used in combination with the walls to guarantee the player will have difficulty getting though. Some people bring their own pickaxe, like rune, to clear rocks/collapse tunnels faster.

Tinderboxes - For setting fire to barricades and catapults. The fires can be put out by buckets of water. It is typically good practice to have a tinderbox in your inventory regardless of your choice of "profession" in your game, whether you're a cleric, warrior, or anything else.

Buckets- Fill them with water at the faucet and the bucket of water is usable to put out anything on fire. These are almost never used though due to the fact that they must be refilled every time they are used and the person that set the fire can easily relight it.

Explosive potion - Used to blow up barricades, unlike tinderboxes they can only be used once. Also used to collapse the cave walls instantly, killing any person running under. If dropped, this potion explodes and deals 15 damage to the player who dropped it (not anyone else). When damaged by this potion, the player also says "Ow!". Many players commit suicide with these to regain health, or prayer.

Castlewars bracelet - Made by enchanting an emerald bracelet. The wielder will do an extra 20% of damage against a bearer of their side's flag. Castlewars bandage also heal 50% more to wielders of the bracelet (15% of health instead of 10%). To obtain the effects of the bracelet, it must be worn as the player enters the game from the waiting room. It may then be removed while retaining its advantages.

Attackers: players who storm the enemy castle either to attack other players or try to capture the flag and bring it back to their own castle

Defenders: players who defend the flag on the second or third floor keeping the enemies from getting a point. Those with freeze spells make good defenders as they can freeze opponents trying to run upstairs. Baricaders may also fall into this catagory.

Archers: players that are located on the outer wall near the catapult that attack incoming enemies players. They may either be rangers or mages.

Medics: players who use bandages to heal other players.

Catapulters: players who attack incoming enemies using the catapult

Door men: players who keep on closing the door on incoming enemies stopping them from coming in and leaving

Baricaders or Engineers: players who set up barricades slowing enemy players down from taking the flag.

Miners: players who go down in the dungeon and clear the way for their team and setting up collapsible rocks on the enemies. They may also try to repeatedly collapse rocks on team mates.

Flag holder: a player who grabs their own flag after an enemy player has dropped it outside their castle and then holds on to it. This player should have a high defense level and be experienced in combat.

Freeloaders: Players who do absolutely nothing but stand around. The most popular spot for freeloading is the small room on the 3rd floor where the trapdoor is at. If there are too many of them, it weakens a team.

Saboteurs: Players who purposefully blow up team baricades, close doors, or anything else that harms their team, so it's easier for the opposing team to win. Like freeloaders, too many of these type of players can harm a team.

Flag holding is a tactic used by teams to ensure that the opposing team is unable to score points. This consists of a player grabbing their own flag after an enemy player has dropped it outside their castle and then holding on to it, rendering the opposing team unable to pick it up. To retrieve the flag the opposing team needs to defeat the player holding the flag and pick it up.

When the opposing team has taken a team's flag, the team wait until their enemy is outside the castle and kill them, taking their own team flag in the process (If the flag is dropped inside the castle, attempting to pick it up will result in it being moved back to the standard stand).

A player cannot go into the base when holding their teams standard (flag). This includes climbing up from the ladder underneath the supply room.

The flag is often taken to a corner of the field with some players protecting it, as a player can be easily protected using two barricades, using the walls as defence from the other two sides.

Another tactic is to hide underground, next to the collapsible walls. The flag holder can then use an explosive potion or a pickaxe to collapse the walls when their enemies try to reach them, thus killing them. One ingenious way of using this method is by placing barricades on the spaces where you can collapse the walls. The flag holder stands in one of the barricades, they put it down, then don't move. This way, if a player tries to attack the flag holder, the flag holder can simply collapse the tunnel. The attacker, having no way to move out of the way, dies. The only way they can reach youu is by going around the other tunnel.

The player that holds the flag will often be someone with a high defence level and bonus or a high level Magic or Ancient Magicks user, players with high levelled Magic or Ancient Magicks can use spells such as Entangle, Ice Burst, or Ice Barrage to immobilize the enemy flag stealers, without the need to hold a weapon. This is advantageous as they can protect themselves using Magic, whereas a player using Ranged will be unable to attack as they will be holding the flag, and a player using Melee will have their attack power compromised by holding the flag, as they will have to use the flag as their weapon. The flag gives no bonuses to Attack, Defense, Strength or Prayer, and has the same attack styles as a spear.

The player will attempt to stay alive for as long as possible, often with a group of players acting as bodyguards. Donating bandages and other supplies to the flag holder may also prove useful.

Another good tactic of holding the flag is to go to the enemy's castle, go behind the table with the barricades, and get a full stock of them. set up two barricades on both sides of the table, and there will be no way to get attacked,unless the other team destroys the barricades.

Perhaps the most common is Ice Barrage, easily stopping the flag carrier's ability to move if it lands. Ice Barrage is the most effective method, but it has the highest level requirement (level 94 magic) and the runes for the spell are expensive.

The least common method is the use of the Jade Bolts (e) passive Earth's Fury, which knocks down the victim when it lands. Low level players who cannot deal high damage but still want to be useful might try this tactic to stun the carrier to give the higher level players more time to kill the carrier.

Some players have argued that this stops the fun, as it stops the game from being "Capture the Flag" and turns it into a "Hunt and Kill" game. They argue that flag-holding is basically unfair as if a high-level player gets the flag, they consider the game to be essentially over, especially if their team does not have a player of matching combat ability.

Following an update, Jagex has prevented this by making 1 of the enchanted bracelets to a Castlewar brace. Castlewars bracelet works for 3 games and is then destroyed. While wearing this bracelet, players will deal 20% more damage to the holder of their flag, and bandages heal 50% more to them.

Castle Wars has had many bugs regarding some aspects of the game remaining active once players had left the game. These include, but are not limited to:

Players remaining as imps, sheep or bunnies after leaving the waiting area.

Players still holding their team standard after a game.

Players having an "attack" option on other players outside of Castle Wars, despite not being able to attack anyone.

Players appearing as if still in the 'dead' position.

Castle Wars games do not have random events. Players used to use Castle Wars as a random-free area in which to cast High Level Alchemy on large numbers of items without being attacked. Because of this, Jagex banned non-combat items from the game and made it impossible to cast alchemy spells on items in the battlefield. Jagex also made it impossible to bring any non-combat items into the waiting rooms. Now players may only bring potions, weapons, and armour into Castle Wars.

The bandage table was once located on the ground floor alongside the other tool tables. This was moved to the team's spawn room due to the fact that opposing players could effectively camp the enemy's castle with an unlimited health source.

At an earlier time, it was possible to leave the game with equipment for the next game, this was soon changed. Players were also able to log out with materials and have them in the waiting room, this also is no longer possible.

When you log out in the game, if you remained logged out for more than two minutes, you will appear in the waiting room once you log in. If you log out in the waiting room, no matter the time, you will be moved to the lobby.

At one time the red and blue decorative armour was equivalent to Mithril. This lowered the price of Mithril, so Jagex updated the red decorative armour to make it the equivalent of steel.

Because of the player having to sacrifice the helmet and cape slot to wear their team colours, the set effects of the Barrows equipment is not active during games of Castle Wars.

Previously, if a player had HP level 99, drank a Saradomin brew, and had the wall in the tunnels collapse on him/her, the player could be hit for more than 100 HP of damage. This is the most damage that can be done in one hit, excluding the Anger Weapons used in A Soul's Bane, which can hit up to 200.